As conventionally well-known power generation systems, there is a package-housed engine generator in which an engine, a generator, and other necessary devices are housed in a package, and a gas turbine cogeneration package in which a gas turbine, a generator, and other necessary devices are housed in a package. Moreover, in a gas turbine cogeneration package, a transformer is disposed on the first-level floor space (e.g., see PTL 1).
In the gas turbine cogeneration package disclosed in PTL 1, devices such as the transformer, the gas turbine, and the generator generate heat during operation, and therefore the space inside the package that houses these devices needs to be ventilated in order to be able to cool the devices. For this reason, gas turbine cogeneration packages and the like have been designed with consideration given to the thermal balance of the whole package including the transformer from the time of manufacturing.